Think you know hostels? Think again. Check out Hopper's picks for 10 of the world's most amazing and unique hostels. These ones go way beyond dorm rooms.

Hostels these days are a far cry from the soiled sheets on creaky bunk beds, stark walls, 30-second shower timers and complimentary breakfasts of dry toast. There are buzzwords for budget accommodation that just didn’t exist 10 years ago, phrases like, "luxury hostel" and "designer hostel," describing places that look closer to boutique hotels than just a place to crash for the night.

How about an evening aboard a repurposed 747 while you wait for an early morning connection, or a glimpse into old world Japan on a tatami in a ryokan? Sleep in a lighthouse overlooking the California coastline, or a treehouse in the wilderness of Turkey, or a literal dug out down under – 11 feet down under, to be specific. Places where no traditional or luxury hotel could find the space to open, are the spaces groomed for budget travelers. These following hostels redefine the idea of budget travel.

10. Castle Rock Hostel in Edinburgh, Scotland

Nestled in the foothills of the grand and imposing Edinburgh Castle Rock, the historic building that now houses Castle Rock Hostel has been around since 1846 and has been restored and updated in design to match the grandeur and elegance of its storied past with a hip and youthful atmosphere that is amenable with backpackers. As such, a stroll around the Castle Rock feels like an art gallery – common rooms are a mix of both hand-picked antiques set against bright wall colors, tourism posters and eclectic pieces. Visitors can enjoy the art of socializing in their movie room, complete with a large projection that screens Scottish and mainstream films, a posh lounge decked out with a piano and fireplace and cushioned "groove" room with walls plastered with framed psychedelic posters and a vinyl player. The views are stupendous – there’s a clear view of the magnificent Edinburgh Castle mere strides from the doorstep, and other angles reveal narrow lanes of long, tall centuries-old buildings with bright storefronts.

9. Kadir's Treehouse in Olympos, Turkey

Wanna get out into the Turkish wilderness but can’t pitch a tent to save your life? Well, the legendary Kadir’s Treehouses offer a backwoods rustic atmosphere with all of the modern amenities of any other hostel and more. This huge hostel looks like an adult sleepaway camp, with wooden huts and log cabin bungalows that house diving centers, open-air cafeterias with a bar, fire pits where guests can gather and sing songs around, and more. Out in what would be considered the Turkish outback of Olympos, visitors can take a bus to visit the eternal flames of the Chimaera, which have been burning for thousands of years from an underground gas field, and walk around the ruins of the ancient city of Phaselis. Visitors can also check out the two tombs in Cirali Beach from the 2nd century A.D., and soak up the sun along the shoreline.

8. Radeka Downunder in Coober Pedy, South Australia

A hostel and attraction in its own right, the Radeka Downunder Dugout Motel & Backpacker Inn is not merely capitalizing on the expression "down under." In the town of Coober Pedy in South Australia, most of the inhabitants live underground in old opal mines or otherwise to escape the scorching heat of the daytime in summer. The Radeka is just a large version of this concept, which encompasses 10 motel rooms, 12 budget rooms and 12 dormitories under layers of sandstone. A former opal mine, the design of this unique motel is simple, which walls of bare sandstone with vents in the naked rock faces. There’s plenty to discover in Coober Pedy – long known as the Opal Capital of the World, the mining industry helped establish this town as a unique tourism destination. Visitors passing by this neck of South Australia can visit underground museums, opal shops, churches and art galleries, play a few rounds in a grassless golf course, check out the old movie sets, and take a scenic tour of Lake Eyre.

7. KEX Hostel in Reykjavik, Iceland

Bright red filing cabinets, wood-tiled ceilings, leather-bound trunks and dangling poolhall lamps all add to the personality of Kex, which is the Icelandic word for "biscuit" and pays homage to the building’s former life as a biscuit factory. Kex prides itself on being a social hostel, and that philosophy is no more obvious than at their Saemundur i Sparifötunum, a gastropub right in the center of the building. It’s social for the guests of the hostel, but it’s also a local watering hole where young Reykjavik residents get together to have a nice meal that isn’t too upscale, enjoy a beer and listen to some jazz.

6. Hostel Celica in Ljubljana, Slovenia

Visitors who decide to stay in Hostel Celica in Ljubljana, the capital of Slovenia, can go home and brag about how they spent a night in a Slovenian prison, bars and all. The story about how this abandoned military facility and political prison turned into a squat for local artists who then left their unique marks on the cell rooms and turned it into a hostel for backpackers is almost as fascinating as a walk around the place itself – there’s a cell with a hanging circular loft bed, elevated platforms, custom designed bunk beds, murals and mosaics and other curious artistic details. The only remaining clues of its dark past are the cell bars that open up to the rooms and the skeleton of the brightly painted building.

5. Gallery Hostel in Porto, Portugal

Fittingly located in the artistic district of Porto, the Gallery Hostel is an eco-friendly luxury hostel housed in a restored 18th century villa. Everything in the hostel has been attended to with artistic consideration, like the art gallery with pieces which change every month, to the themed nightly dinner, the manicured winter and rooftop gardens, and a free tour through the art district itself. Luxury hostel might seem like an oxymoron, but this hostel makes a great case for it: for the price of a hostel, guests receive a pristine, modern and tastefully designed dorm room with punchy colors (with an ensuite bathroom), common spaces that look straight out of a magazine (think polished darkwood floors and huge colorful prints on the walls), a computer center stocked with Macs, and a free breakfast that will make one scorn every free breakfast they ever have afterwards.

4. Point Montara Lighthouse Hostel in Montara, California

The historic Point Montara Lighthouse Hostel, perched on a bluff overlooking the Pacific Ocean merely 25 miles from San Francisco, was originally established in 1875 as a fog signal station and is still operating as an aid-to-navigation maintained by the U.S. Coast Guard. Guests stay in shared and private rooms in the former Coast Guard quarters and the fog signal building, where they can admire the view from the coast. This minimal and homey hostel is located right next to a beach and is ideal for visitors interested in exploring nearby Half Moon Bay.

3. K’s House Ito Onsen in Ito, Japan

Located along the banks of the Matsukawa River in Ito is a historic century year old ryokan – a traditional Japanese inn – built in the typical Ito style of thin wooden walls and rice paper screens. A few modern adjustments have been made to K’s House to accommodate its visitors, like air conditioning and Internet access, but the noble historic culture remains pervasive – guests stay in minimalist tatami-style rooms with low, flat bed mats (imagine a hostel without bunk beds!), paper screen details, and male and female hot spring baths located directly on the site.

2. Cabo Polonio Hostel in Cabo Polonio, Uruguay

In a village with no electricity or running water (energy is absorbed through solar panels and water is taken from local wells that collect rainwater), located on a protected national park on a peninsula facing the glorious expanse of the Atlantic Ocean, business and leisure are conducted either on the undulating sand dunes or in the wooden beach houses speckled along the coastline. One such beachhouse is the Cabo Polonio Hostel, a brightly painted wood and straw shack topped with a corrugated tin roof. Guests can lie on the hammocks and sway through the afternoon with a totally unobstructed view of the ocean, enjoy the owner’s gourmet creations, hike the forests of pine and Ombu trees, surf, and learn and enjoy the simple life.

1. The Jumbo Stay Hostel in Stockholm, Sweden

Budget travelers to Stockholm don’t have to miss out on all of the unique and innovative Swedish-designed accommodations – the Jumbo Stay hostel houses their rooms in a real, decommissioned and restored Boeing 747 from 1975. Located next to its architectural brethren at the Stockholm Arlanda Airport, this jumbo jet was meant for a purpose beyond the skies – its totally modern stark-white interiors accented by small punches of color and an efficient and space-saving design are ideal for those hoping to save a dime, but it’s certainly a world away from economy class. Visitors with a curiosity and a bigger budget can book the Cockpit Room, with spectacular views from the hump, but those on a casual overnight can take any of their four-person Jumbo Stay rooms and suites. In the summer, the hostel opens up its outdoor patio, so guests can grab their breakfast and sit right on the wing.